Rotary engine.



, B. F. HOFFMAN.

V. ROTARY ENGINE. APPLICATION FILED JULY 15, 1908.

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B. F. HOFFMAN.

ROTARY ENGINE.

APPLICATION FILED JULY 15, 1908.

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' BERTRAM F. HOFFMAN, OF BUFFALO, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO BALANOE'PBESSURE ROTARY ENGINE COMPANY, OF BUFFALO, YORK, A CORPO- BAT-ION or NEW YORK.

ROTY EN Specification of Letters Patent.

Patented April 13. 1909.

To all {whom it may concern: 7 Be it known that I, BERTRAM F. Horr- MAN, a citizen of the United States, residing at'Buffalo, in the county of Erie and State of New York, have invented a new and use ful I m rovernent in Rotary Engines, of which t e following is a specification.

This invention relates more particularly to improvements in rotary steam engines of that type which comprises essentially a rotary cylinder, a core or part which is arranged eccentrically within the cylinder in contact therewith at one side and rotates in the same direction as the cylinder, and a piston or blade which is secured to the cylinder and I bridges the space betweenthe same and the core and against which the steam acts in turn- .ing the cylinder which is connected to the drive shaft and constitutes the driving element of the en ine. The steam pressure in the piston cham er tends to separate or force the core and cylinder apart, which ca'usesthem to turn on their bearings in the same direction, the core rolling around within the cylinder.

The primary object of this invention is to provide rolling bearings for the cylinder and the core whereby the core is maintained in rolling contact with the cylinder, and antifriction' bearings are at the same time pro-' vided which receive the opposing pressures on the core and c linder and prevent excessive friction and Wear thereon. Another object of the invention is to improve rotary engines of this type in the respects hereinafter described and set forth in the claims. k

In this application a multiple cylinder engine is described and illustrated having two piston chambers with a core and piston in each chamber, andmeans for admitting .and .using the steam first in one piston "chamber, then admitting the expanding steam from this chamber into the second chamber .while the ex )osed area of .the piston in the first chain er is decreasing and the exposed area of the piston in the second I chamber is increasin and finall mg the steam from t e second camber, so

exhaustas thereby .to .secure in an engine'ofsmall size the effect of a long travel of a piston of maximum and substantially constant area .foreach admission of the steam and obtain the maximum efiiciency of the steam used. .Most .features .of the invention are not,

however, restricted to multiple cylinder y engines of this sort, but are equally applicable to single cylinder engines or multi-stage engines of other types! n the accompanying drawings, consisting of two sheets: Figure 1 is a longitudinal sectional elevation, in line 1-1, Fig. 2, of a multiple ylinder rotary engine. embodying the invention. Fig; 2 is a transverse sectional elevation thereof through the primary piston chamber, in line 2-2, Fig. -1. Fig. 3 is a sectional plan thereof in line 3-3, Fig. 2. Fig. 4 is a fragmentary transverse sectional elevation thereof, substantially in line 4-4, Fig. 1. Fig. 5 is a fragmentary transverse sectional elevation in line 5-5, Fig. 3, showing the roller bearings for the cylinder and cores.

Like letters of reference refer to like parts w in the several figures.

A represents the rotary cylinder; B B two rotary cores arranged eccentrically in two piston chambers a a. in the cylinder in contact at one side with the cylindrical walls thereof; C the rotary drive shaft; D D the The drive shaft C extends through the cylinder eccentrically thereto and is ournaled at 0p osite ends in suitable bearings c on the en s of the inclosing casing. The drive shaft passes centrally through and supports the cores B B which are loose and adapted to turn thereon, and is connected to the cylinder independently of the cores so as tobe positively driven by the cylinder, preferably y a slotted arm 0', Figs. 1 and 4, which is fixed to the shaft in the middle cylinder chamber or space a and a .pin a secured to the cylinder in the middle cylinder chamber a? and passing throu h a radial slot in the arm a. A cross-hea c throu h which the pin 0 passes, slides radially t 1e slot of .the arm 0'. This connection causes the shaft .to turn positively with the cylinder but the sliding engagement between the arm and the pm allows for the necessary movement of the connecting pin toward and from the shaft due to the eccentric arrangement of the shaft in the cylinder. The pistons or blades D D are suitably secured rigidly to the cylinder and extend inwardly therefrom. across the steam spaces between the cylinder and cores into ockets d in the cores. Segmental bearing locks d, or other means, are provided between the pistons and the sides of the piston pockets (1 to allow the pistons to slide radially and oscillate in the pockets in the operation of the engine and prevent thesteani from passing t e pistons. The pistons or blades cause the cores to turn with the cylinder in the operation of the engine, but the cores are loose on the drive shaft 0 and the shaft is positively driven by the cylinder independently of the cores by the connecting arm 0 and pin 0 and consequently the friction and wear between the pistons or blades and the cores are greatly reduced. Furthermore, as the drive shaft, upon which the cores bear, is turned in the same direction as the cores, there is only a relatively short slipping or oscillating movement of the cores on the shaft due to their eccentricity in the cylinder, so that the friction and wear between these parts are also very slight.

F represents bearing rollers upon which the hubs or bearing flanges a at the ends of the cylinder rest and turn, and F represents bearing rollers arranged at o posite sides of the hubs or flan es of the cy inder and contacting therewit to revent lateral motion of the cylinder on the caring rollers F. The axes of the side rollers F are referably arranged on" or slightly below t e horizontal plane of the axis of the cylinder, so that while they prevent lateral motion of the cylinder they do not prevent the same from liftin "he lower and side bearin rollers F and F are journaled in any suitab emanner, for instance, as shown, they turn on shafts f andf which engage at opposite ends in bearings and f on the opposite ends of the inclosing casing.

G G represent two bearing rollers which turn loosely on the drive shaft 0 within the hubs or flanges a of-the cylinder and bear on the inner surfaces ,of. said hubs or flanges at a point above the point of contact of saidv hubs or flanges with the lower bearing rollers F. The pressure of the steam in the piston cham ers between the cores and cylinder tends to lift the cylinder and forcibly press the cores downwardly against the lower Eortion of the cylinder, but the shaft rollers bearing against thehubs or flanges a of always act directly in a vertical line, but the side-bearing rollers F prevent any lateral play of the cylinder dueto lateralpressure of the steam, andthe shaft'rollers G are always held against the lower portion of the bearing flanges or hubs ofthe cylinder. This arrangement of the bearing rollers insures the necessary contact between the cores and cylinder but prevents excessive pressure of the cores against the cylinder so as to reduce the friction and wear on these contacting surfaces. The rollers provide rolling or antifriction bearings for both the cores and cylinder.

As usual, in engines of this type, the steam is admitted to and exhausted from each piston chamber through suitable port's at oppocylindrical we 1 of the cylinder from the first piston chamber a to the second piston chamber a" at a point in rear of the piston D, and an exhaust passage M leads from the second piston chamber through the wall of the cylinder at a point in front of the piston D In the operation of the engine the steam enters the first piston chamber in rear of the piston D through the passage 7c in the core B and causes the cylinder and core to turn in the clockwise direction indicated by the arrow in Fig. 2. When the intermediate passage L passes the point of contact of the'core' D with the cylinder, the expanding steam will flow through this passage into the second Biston chamber in rear of the second piston and act on this piston. ,The steam in the first piston chamber in front of the piston D flows through the, intermediate passage L into the second piston chamber and the steam in this chamber in front of the piston D escapes through the exhaust port M-into the lnclosing casing E, from which it passes off through a pipe not shown. The steam thus acts first on one piston and then on the second in the same direction, causing the engine. to rotate in the'direction indicated.

A suitable valve or valves is or are ordinarily provided to properly time the admission and cut-off-of the steam to the engine, yielding packing or contact strips are provided between the cores and the inner surface of the cylinder, and suitable means are of course employed for packing such joints of the engine as may be necessary, but these and other incidental features of the engine form no part of this invention and are not shown or described.

The described roller bearings are applicable to either single cylinder engines or other types of multiple cylinder engines, and the particular connecting means between the cylinder and drive shaft is applicable to multi-stage engines of other kinds employing the cylinder and eccentric cores rotating in the same direction. These features are also applicable to pumps, and other mechanisms similar in organization to the engine described.

I claim as my invention:

1. In a rotary engine or the like, the combination of a rotary cylinder, a'core which is arranged eccentrically in the cylinder and I rotates therewith, a piston connecting the cylinder and core, bearings for the cylinder, supporting means for the core, and rollers connected to the core-supporting means con centrically with the axis of the core and bearing on portions of the cylinder concentric with the axis thereof, substantially as set forth.

2. In a rotary engine or the like, thecombination of a rotary cylinder, a core which is arran ed eccentrically in the cylinder in con tact t ierewith at one side, a piston which is secured to one of said parts and has a movable connection with the other part whereby said core and cylinder turn in the same di-- rection, bearings for the cylinder, supporting means for the core, and rollers connected to the core-sup orting means concentrically with the axis 0 the core and bearing on portions of the cylinder concentric with the axis thereof, substantially as set forth. I

3. In a rotary engine or the like, the combination of a rotary cylinder, a core which is arranged eccentrically in the cylinder in contact therewith at one side, a iston connecting the cylinder and core, rol ier bearings on which the cylinder rests, a shaft which supports the core, and rollers on said shaft which ear on portions of the cylinder concentric with its axis, substantially asset forth.

4. In a rotary engine or the like, the combination of a rotary cylinder, a core which is arranged eccentrically in the cylinder in contact therewith at one side, a iston connecting the cylinder and core, rol er bearings for the cylinder, a shaft on which the core turns, roller bearings between the cylinder and core, and a drive connection between the cylinder and said shaft for turning the shaft, substantially as set forth.

5. In a rotary engine or the like, the combination of a rotary cylinder, a core which is arranged eccentrically in the cylinder in contact therewith at one side, a piston connecting the cylinder and core, said cylinder having concentric bearing flanges, bearing rollers on which said flanges rest, a shaft which supports the core, and rollers on said shaft which bear on the inner surfaces of said bearing flanges, substantially as set forth.

6. In a rotary engine or the like, the combination of a rotary cylinder, a core which is arranged eccentrically in the cylinder in contact therewith at one side, a piston connecting the cylinder and core, said cylinder having concentric bearing flanges, bearingrollers on which said flanges rest, a shaft on which the core turns, bearings in which said shaft is journaled, rollers which are loose on said shaft and bear on the inner surfaces of said bearing flanges, and a drive connection between the cylinder and said shaft for turning the shaft, substantially as set forth.

7. In a rotary engine or the like, the combination of a rotary cylinder, a core which is BERTRAM F. HOFFMAN. Witnesses:

C. B. HoRNBEoK, C. W. PARKER. 

